Propeller



Jan. 5, 1932. E SEPPELER 1,839,347

PRQPELLER Filed April 5, 1929 2 Sheets-Shem-l 1 Nl/enor: v www I l 2cd ,JUL 5, 1932 E. SEPPELER 1,839,347

PROPELLER Filqd April 5, 1929 2 Sheets-Sheet 2 Il? f77 Ven for.'

/9 www Patented Jan. `5, 1932 UNITED STATES PATlazNT OFFICE PBOPELLEB Application ed April 5, 1929, serial No. 352,676, and in Germany yDecember 5, 1925.

My invention relates to propellers which may be designed to transmit or absorb power and may operate in gaseous and liquid media. It is an o ject of my invention to provide '5 means for regula-ting the position of the pro.- peller blades in con ormity with the thrust, the weight or the velocity of the driving or driven medium, with the power delivered or absorbed, or with other factors.

To this end I provide means for applying t the .propeller blades centrifugal, spring and residual medium forces, such as air forces in a propeller for aerial craft.

It has already been proposed to adjust the blades of a propeller by a force resulting from the opposite action of centrifugal and thrust forces, the blades being moved backwards or forwards in conformity with the variations l of the thrust and their movement being uti# lized for turning the blades by means of links or cam faces.

It has also been proposed to arrange the blades for axial displacement with respect to the propeller shaft, to transmit to a com'- ression spring a reaction of the centrifugal orces exerted by'the blades upon their ax` ial displacement and to translate such axial displacement of the blades into turning movement of the blades about their axes by means of. cam faces.

In the drawings aixed to this specification and forming part thereof two types of Propellers embodying my invention are illustrated diagrammatically by way of example.

In the drawings Fig. 1 is a plan view of the first type, Fig. 2 is a section on the line 2-2 in Fig. 1, Fig. 3 is a section on the line 3-3 in Fig. 2, Fig. 4 is an' end elevation of the second type, and

Fig. 5 is a section on the line V-V in Flg. 4.

Referring to the drawings, 3 is the propeller shaft, 4 is a boss at the end of the shaft, 1 and 2 are propeller blades, each with a stem 13. such stem being supportedv for rotation about the common axis of its blade in suitable bearings 13, for instance ball bearings, in the boss 4, and 5 and 6 are balance weights at the end of the stem 13 of each 5 blade, respectively, which are arranged eccentrically with respect to the axis of the correspondinblade, as can best be seen in the we1ght 5 in ig. 4, the balance weights belng provided for the purpose of placing the centre of gravity of each blade into a plane Il vcomcident with the axis about which the propeller is rotating. A

7 is a through-bore in the boss 4 which is arranged. atright angles to the stems 13, or substantially so. 8 and 9 are balance weights 5 which are tted to slide `in either end of the bore 7 in radial direction with respect to the axis of the propeller shaft 3; 11 and 12 arc pulleys or sectors on the stems 13 of the propeller blades, 10 is a spring housed in an 55 axial extension 4 of the boss 4, and 14 and 1,5 are cables which are secured to the spring 10 at one end, to one of the weights 8, 9 at the other end, and supported intermediate their ends on the pulleys or sectors 11, 12, or attached to such pulleys. It will appear that the points where the cables 14 and 15 are connected with the spring 10 are in the extension of tangents to the pulleys 11 and 12. rIfhe contraction of the spring 10 is limited by flanges at the ends of the weights 8, 9. y

When the propeller rotates about its shaft 3, a torque resulting from centrifugal action is generated in all parts which are arranged eccentrically with respect to the axis about which each blade is adapted yto turn, this torque turning each bladeabout its stem 13 until the torque isbalanced by the reaction of the spring 10. By means of the cables 14,

15 the forces resulting from deformation of 55 the spring 10, variations in the position of the blades, residual medium (air) forces and all inertia forces tending to turn the blades are positively interrelated, even if the several factors are not equalto each other. If the amount, for which the blades require adjusting is small, the weights 8, 9 may be dispensed with and only the centrifugal action of the weights turning with the-blades, the eccentric weights 5, 6, and/or the pulleys 11, 12 may be relied on for adjusting the blades, and if the amount is smaller-still, the cables 14, 15 may be displaced by links (not shown) (ionnecting the blade stems 13 with the spring Instead of a single cable for each blade, two or a plurality of (parallel cables may be provided and attache to diametrlcallyppposite points on the perimeter of the sprmg. In this case the cables do not extend in the axial plane of the system and therefore the propeller shaft 3 may be extended into the boss and through thc spring 10 as far as the end of the axial extension 4, as shown in Fig. 4, with a nut 33 at its outer end.

An example for this arrangement of cables is shown in Fig. 4, in which, however, the spring 10 is secured on the outside of the extension 4. Instead of a single pulley 11 or 12 at the centre of each stem 13, as shown in Fig. 3, pulleys 11', 11" and 12, 12 are :1rranged on the stem at either side of the boss 4. Each pulley supports a cable 14 or 15 and these cab es are attached to the spring 10 by shackles 14 and 14", Fig. 5, so that the reaction of the spring is transmitted to each blade by a cable at either side of the extension 4. The contraction of the sprin 10 is limited by checks 16 which are engage by shoulders on the pulleys, the shoulders 34 and 35 of the pulleys 11 and 12', respectively, being visible in Fig. 4. It will be understood that in this type thesha'ft 3 may extend as far as the end of the extension 4.

I have illustrated a type of propeller in which eccentric weights 5 6on the blade stems 13 are combined with welghts 8 9, which can be displaced in radial direction, as shown in Figs. 1, 2 and 3, and in Fig. 4 I have illustrated a propeller in which the centrifugal weights 8, 9 are dispensed with and onl the eccentric weights 5 and 6 are provided, ut I wish it to be understood that in the modification illustrated in Fig. 4 I may provide the centrifugal weights 8, 9 in combination with the eccentric weights 5, 6, and that in the type illustrated in Figs. 1 to 3, I may dispense with the eccentric weights 5, 6 or with thc centrifugal weights 8, 9, as required, without departing from my invention.

The faces of the blades may be so positioned with respect to the axis, about which each blade is adjusted, that the thrust forces are either absorbed altogether by the bearings 13 of the blade stems 13 or are utilized for assisting the spring 10 or the inertia forces in the form of a residual torque, for the purpose of influencing the regulating characteristie.

The operation of the new device is very efficient and reliable and absolutely uniform speed of revolution has been obtained, independently of the load, in a wind tunnel at air velocities of 20 to 50 metres per second.

In some of the claims, a lever arm is referred to. It is understood that this term was selected for the radial arm at which the forces act on the stems 13, for instance at the perimeter of the pulleys or sectors 11, 12.

I wish it to be understood that I do not desire to be limited to the exact details of served.

1. A propeller comprising avshaft, two blades adapted to rotate bodily with said propeller and to turn about their own axes, a spring on said propeller arranged coaxially to said shaft and connected with said two blades so as to expose itself to their turning about their respective axes and rotary means operatively connecting said spring to said blades which rotary means are so designed that said spring acts uniformly on both blades. i

2. A propeller comprising a shaft, two blades adapted to rotate bodily with said propeller and to turn about their own axes, a spring on said propeller arranged coaxially to said shaft and connected with said two blades so as to oppose itself to their turning about their respective axes, and a weight arranged to be subjected to centrifugal action when said propeller is rotating', and so positioned with` respect to said sprin as to counteract the action exerted by sai spring on said blades.

3. A propeller comprising a shaft, two

blades adapted to rotate bodily with said propeller and to turn about their own axes, a spring on said propeller arranged coaxially to said shaft and connected with said two blades so as to oppose itself to their turning about their respective axes and a balance weight on each blade which 1s so arran ed as to place the centre of gravity of said lades into a plane coincident with the axis, about which said propeller is rotating.

4. A propeller comprising a shaft, two blades adapted to rotate bodily with said propeller and 'to turn about their own axes, a spring on said propeller arranged coaxially to said shaft and connected wlth said two blades so as to oppose itself to their turning about their respective axes, and a balance weight on each blade arranged eccentrically with respect to the axis of said blade so as to place the centre of gravit of said blades into a plane coincident wit the axis, about which said propeller is rotating.

5. A propeller comprising a shaft, a boss on said shaft, two blades arranged in said boss so as to be capable of turning about their axes, a spring on said boss arranged coaxial- 1y to said shaft and means for deforming said spring 1n dependency from the rotation of said blades.

' lever arm on each stem, a spring on sald boss arran ed coaxially to said shaft and connecte to said arm, a centrifugal weight also connected to said arm in such manner that its centrifugal action will counteract the ressure of said spring and an eccentric weig t on said stem. l v

7. A propeller comprising a shaft, a boss on said shaft, blade stems in said boss, lever arms spaced axiallyv on each stem and a sprin on said boss arranged coaxially to said s aft and connected to said arms.

8; A propeller comprising a shaft, a boss on said shaft, blade stems in said boss, a pulley on each blade stem, and a. spring on said boss connected to said pulley.

shaft, a boss 9. A propeller comprising a on said shaft, blade stems in said boss, pulleys on each blade stem on either side of said boss, a spring on said boss, and cables connectmg said spring and said pulleys.

In testimony whereof I aix my s' ature.

EDUARD- SEPl R. 

